Racial/ethnic minorities are under-represented in virtually all areas of medical research. The reason for this current underrepresentation continues to elude investigators. This study provides insight into the factors affecting African-American medical research participation. Specifically, this study examines 1) the major factors influencing African-American willingness to participate in medical research; 2) barriers and impediments to African-American participation in medical research differ between African-Americans and Caucasians; 5) whether impediments to medical research participation are more prevalent in African- American than Caucasian households; 6) whether distrust accounts for the differences in medical research participant rates between African-American and Caucasian households; 7) whether African- Americans have similar opportunities to participate in medical research as Caucasians; and 8 whether African-Americans knowledge of the Tuskegee Syphilis Study influences their medical research participation decisions. This information will assist researchers in developing racially appropriate recruitment strategies for African-American subjects. A multistage area probability sample of 600 households from a total of 1.5 million households in the Detroit Primary Statistical Area are selected to receive a mail questionnaire. The sampling plan is designed to provide a nearly equal number of African-Americans and Caucasian respondents without pre-screening for race. African- Americans are over-sampled at a rate of 4:1. Stratification, disproportional sampling are also employed in a effort to achieve a racially and socioeconomically balanced sample.